761 M (or those of an aspirin-treated normal to convert P.G. G2 to thromboxane A2 were unable but subject) of thromboxane synthetase. Hence, his to a deficiency owing platelets would show diminished aggregation responses to P.G. G2, as well as other aggregating agents. Further studies are in progress to characterise the defect in patients K and M, but these preliminary observations suggest that, in some congenital disorders, the synthesis of thromboxane A2 may be inhibited at a site subsequent to the formation of P.G. G2 (leaving the prostacyclin pathway intact) and that this type of inhibition may be achievable by pharmacological means as well.
platelets of patient
Roosevelt Hospital, New York 10019, U.S.A., and Columbia University, College of Physicians and Surgeons, New York
HARVEY J. WEISS BRUCE A. LAGES
SERUM-HIGH-DENSITY-LIPOPROTEIN AND UNIVERSITY GROUP DIABETES PROGRAM RESULTS
SIR,-The University Group Diabetes Program (U.G.D.P.) concluded that treatment with oral hypoglycaemic agents (tolbutamide or phenformin) led to an excess cardiovascular mortality.’The reason for this is not clear. Lopes-Virella and ColwelP have reported decreased a-lipoprotein and high-density-lipoprotein (H.D.L.) cholesterol levels in diabetics but without reference to age, sex, or type of treatment. We have measured lipoprotein levels in elderly diabetics on insulin or oral therapy. The patients were matched for age and had been CHOLESTEROL, TRIGLYCERIDE, AND LIPOPROTEIN FRACTIONS IN DIABETIC PATIENTS, 12 ON INSULIN AND 11 ON ORAL THERAPY
This work is supported by the United States Israel Bi-national Science Foundation grant no. HANOCH BAR-ON Department of Medicine B,
604.
Hadassah University Hospital, P.O.B. 499, Jerusalem, Israel
DANIELLA LANDAU ELLIOT BERRY
ABO BLOOD-GROUP DISTRIBUTION AND
ISCHÆMIC HEART-DISEASE
SIR,-Professor Mitchell’s paper (Feb. 5, p. 295) will reawaken interest in possible relationship between blood-group distribution and ischaemic heart-disease (I.H.D.). People with blood-group A or AB have a higher serum-cholesterol than those with blood-group 0 or B,1and blood group A is more common than expected in atherosclerosis.3 This difference in serum-cholesterol between the blood-groups is present at birth.4 A large male population survey revealed that pathological Q waves were significantly more frequent in men of blood group A or AB than in men of group B or 0. Men with bloodgroup A or AB also had a significantly higher frequency of a history of parental death before the age of 60 years.2 Within a population the blood-group distribution varies with age, especially above the age of 50,2 so age should be taken into account whenever blood-group distributions are compared. In a follow-up study of 42 804 men we found that the death-rate in those due to I.H.D. was 28% higher than expected (p
platelets of patient
Roosevelt Hospital, New York 10019, U.S.A., and Columbia University, College of Physicians and Surgeons, New York
HARVEY J. WEISS BRUCE A. LAGES
SERUM-HIGH-DENSITY-LIPOPROTEIN AND UNIVERSITY GROUP DIABETES PROGRAM RESULTS
SIR,-The University Group Diabetes Program (U.G.D.P.) concluded that treatment with oral hypoglycaemic agents (tolbutamide or phenformin) led to an excess cardiovascular mortality.’The reason for this is not clear. Lopes-Virella and ColwelP have reported decreased a-lipoprotein and high-density-lipoprotein (H.D.L.) cholesterol levels in diabetics but without reference to age, sex, or type of treatment. We have measured lipoprotein levels in elderly diabetics on insulin or oral therapy. The patients were matched for age and had been CHOLESTEROL, TRIGLYCERIDE, AND LIPOPROTEIN FRACTIONS IN DIABETIC PATIENTS, 12 ON INSULIN AND 11 ON ORAL THERAPY
This work is supported by the United States Israel Bi-national Science Foundation grant no. HANOCH BAR-ON Department of Medicine B,
604.
Hadassah University Hospital, P.O.B. 499, Jerusalem, Israel
DANIELLA LANDAU ELLIOT BERRY
ABO BLOOD-GROUP DISTRIBUTION AND
ISCHÆMIC HEART-DISEASE
SIR,-Professor Mitchell’s paper (Feb. 5, p. 295) will reawaken interest in possible relationship between blood-group distribution and ischaemic heart-disease (I.H.D.). People with blood-group A or AB have a higher serum-cholesterol than those with blood-group 0 or B,1and blood group A is more common than expected in atherosclerosis.3 This difference in serum-cholesterol between the blood-groups is present at birth.4 A large male population survey revealed that pathological Q waves were significantly more frequent in men of blood group A or AB than in men of group B or 0. Men with bloodgroup A or AB also had a significantly higher frequency of a history of parental death before the age of 60 years.2 Within a population the blood-group distribution varies with age, especially above the age of 50,2 so age should be taken into account whenever blood-group distributions are compared. In a follow-up study of 42 804 men we found that the death-rate in those due to I.H.D. was 28% higher than expected (p
